This continuation study will investigate links between participation in an established, federally-funded early childhood intervention and adult well being up to age 30 for a large cohort of children (93% African American) in the Chicago Longitudinal Study who grew up in high poverty neighborhoods. Five major questions are addressed: (a) Is participation in the CPC preschool program associated with greater well being for educational attainment, economic self-sufficiency, social behavior, health status and behavior, and mental health 20 to 25 later?, (b) Are the effects of participation in extended intervention for 4 to 6 years greater than participation in less extensive or unsystematic intervention?, (c) Do the estimated effects of program participation vary by child and family risk, program attributes, and neighborhood factors?, (d) Do the cognitive advantage, family support, and school support mechanisms of intervention effects persist to age 30?, and (e) Do the economic benefits of participation in the CPC program continue to exceed costs and by how much? By further expanding the project into adulthood, the proposed study will document the impact and cost- effectiveness of early intervention across a wide range of rarely investigated outcomes. No other studies of publicly-funded early childhood programs have continued through the third decade. The study sample of 902 program and 487 comparison-group participants represents 91% and 89% of the original sample, respectively. Over the next five years, we will obtain and analyze a comprehensive set of new data from educational, justice system, public aid, and social-service records, conduct follow-up interviews for the entire sample at age 29/30, and analyze existing data from multiple sources. The key long-term goals are (a) to increase knowledge about the adulthood effects of early intervention, including its timing and duration, (b) to identify the enduring mechanisms through which early interventions affect well being over the life course, and (c) to determine the cost effectiveness of intervention relative to other social programs.